TALDYQORGHAN, Kazakhstan -- A court in Kazakhstan has sentenced five men to prison terms ranging from 18 to 20 months after convicting them for being members of a banned Islamic group.

A court in the southeastern city of Taldyqorghan delivered the verdicts and sentences late on January 15.

Investigators say the men have spent time in Bangladesh, where they studied at an Islamic school and joined an Islamic group called Tablighi Jamaat, which is officially banned in Kazakhstan, Russia, Uzbekistan, Tajikistan, and Russia.

The prosecutor said at the trial that after returning to Kazakhstan, the men propagated extremist views and tried to attract new members to their group.

One of the defendants pleaded guilty while the other four pleaded not guilty, saying they are being persecuted for being Muslims.

Islamic groups have been under increased scrutiny from the Kazakh authorities since a suspected Islamist militant carried out the country's first-ever suicide bombing in the northwestern city of Aqtobe in 2011.